This invention relates to air driven centrifuges and, more particularly, is directed to a self adjusting rotor seat for use with an air driven centrifuge to provide stable movement of the rotor in all phases of operation of the rotor.
Reference is made to U.S. Pat. No. 4,046,317 which discloses a uniquely designed rotor seat and corresponding rotor which operate in conjunction with levitation air to provide the desired stability in the operation of the rotor especially during deceleration of the rotor. More specifically, the referenced patented invention utilizes the unique design of the rotor seat and the lower portion of the rotor to form a flow path for the levitation air, so that the movement of the air between the rotor and the rotor seat enhances the retention of the rotor within the rotor seat. Also, the particular configuration of the rotor and rotor seat aids in the maintenance of the proper alignment of the rotor with its rotational axis. At the critical or threshold speeds during deceleration the rotor must not experience any precessional or wobbling movement, because this detrimental movement would invalidate the centrifugation run or in extreme cases cause the rotor to escape the rotor seat and thrash around within the centrifuge housing. The levitation air with the design shown in U.S. Pat. No. 4,046,317 allows the rotor to smoothly decelerate and float on a friction free cushion of levitation air.
However, in order to provide the optimum design and configuration between the conforming surfaces of the rotor seat and the lower portion of the rotor, it is necessary that these particular portions of the centrifuge be manufactured with extremely close tolerances. The dimensions are very critical with respect to the operation of the air driven rotors at extremely high rotational speeds such as 150,000 r.p.m. to 200,000 r.p.m. If the design tolerances are not properly met in the construction of the centrifuge, improper rotation of the rotor may occur during these high speeds as well as the critical threshold speeds that occur not only during deceleration, but also during acceleration while the rotor is between its operating speed and its stationary position.